Marking articles using a covert digitally watermarked image

Abstract

A marking system that includes forming at least one marking in or on an article, wherein the image formed is not visible to the unaided human observer, and further contains at least one digital watermark. The digitally watermarked image comprises emissive and photoabsorptive portions. The digitally watermarked image is applied using a substance reactive to a predetermined excitation source, and exposure to ultraviolet light. Other traditional techniques, such as printing with fluorescent inks may be used in combination. The digitally watermarked image is subsequently observable upon exposure to the predetermined excitation source. The digitally watermarked image may be observed and decoded by appropriately configured detection systems, wherein the information obtained may be used for purposes including, but not limited to, authentication and security of the article or information contained within the article.

1. An object comprising at least one digitally watermarked image, said digitally watermarked image being normally invisible and comprising a material that causes said digitally watermarked image to become detectable due at least in part to an optically absorptive property of said digitally watermarked image when exposed to a predetermined excitation source, wherein the optically absorptive property of the digitally watermarked image is formed as a result of irradiation of the material. 
   
   
     2. The object as in  claim 1 , wherein said digitally watermarked image includes a data code symbology comprising at least one of a bar code, a graphic, text, and alphanumeric characters. 
   
   
     3. The object as in  claim 1 , wherein said digitally watermarked image comprising at least one digital watermark is disposed upon said object in a coating. 
   
   
     4. The object as in  claim 3 , wherein said coating comprises at least one of a polymeric material, a monomeric material, a metal chelate, an organic phosphor, an inorganic phosphor, a fluorescent dye and a laser dye. 
   
   
     5. The object as in  claim 1 , wherein said digitally watermarked image comprises information for purposes comprising at least one of authentication of said object, providing a relationship to said object, providing access to a digital watermark, providing access to said object, providing access to information contained within said object, and providing a key for decrypting encrypted information. 
   
   
     6. The object as in  claim 1 , wherein said digitally watermarked image comprises a decryption key. 
   
   
     7. The object as in  claim 1 , wherein said object comprises one of an optical media, a security document, a note of currency, a product package, a label, an identification, and a credit card. 
   
   
     8. The object as in  claim 1 , wherein the object has a data readable side and a non-readable side. 
   
   
     9. The object as in  claim 1 , wherein the object is an optical disc. 
   
   
     10. The object as in  claim 1 , wherein the digitally watermarked image comprises a latent contrast formation produced by photobleaching. 
   
   
     11. An article comprising a marking, the marking comprising: a first digitally watermarked image, said digitally watermarked image being normally invisible and comprising a material that causes said digitally watermarked image to become detectable due at least in part to an optically absorptive property of said digitally watermarked image when exposed to a predetermined excitation source; and, a second digitally watermarked image disposed upon said article, wherein said second digitally watermarked image is substantially observable to the unaided observer, wherein the optically absorptive property of the first digitally watermarked image is formed as a result of irradiation of the material. 
   
   
     12. An article as in  claim 11 , wherein said first digitally watermarked image is in registration with said second digitally watermarked image. 
   
   
     13. An article as in  claim 11 , wherein said first digitally watermarked image is offset from said second digitally watermarked image. 
   
   
     14. An article as in  claim 11 , wherein said first digitally watermarked image is concentric with said second digitally watermarked image. 
   
   
     15. An article as in  claim 11 , wherein said first digitally watermarked image and said second digitally watermarked image each comprise at least a complimentary portion of a complete digitally watermarked image of said marking. 
   
   
     16. An article as in  claim 11 , wherein at least one of said digitally watermarked images comprises information for purposes comprising at least one of authentication of said article, providing a relationship to said article, providing access to a digital watermark, providing access to said article, providing access to information contained within said article, and providing a key for decrypting encrypted information. 
   
   
     17. An article as in  claim 11 , wherein at least one of said watermarks comprises a decryption key. 
   
   
     18. An article comprising a marking, the marking comprising: a first digitally watermarked image, said digitally watermarked image being normally invisible and comprising a material that causes said digitally watermarked image to become detectable due at least in part to an optically absorptive property of said digitally watermarked image when exposed to a first predetermined excitation source; and, at least one second digitally watermarked image, said second digitally watermarked image being normally invisible and comprising a material that causes said second digitally watermarked image to become detectable when exposed to a second predetermined excitation source, wherein the optically absorptive property of the first digitally watermarked image is formed as a result of irradiation of the material. 
   
   
     19. An article as in  claim 18 , wherein said first digitally watermarked image is in registration with said at least one second digitally watermarked image. 
   
   
     20. An article as in  claim 18 , wherein said first digitally watermarked image is offset from said at least one second digitally watermarked image. 
   
   
     21. An article as in  claim 18 , wherein said first digitally watermarked image is concentric with said at least one second digitally watermarked image. 
   
   
     22. An article as in  claim 18 , wherein said first digitally watermarked image is overlapping with said at least one second digitally watermarked image. 
   
   
     23. An article as in  claim 18 , wherein at least one of said digitally watermarked images comprises information for purposes comprising at least one of authentication of said article, providing a relationship to said article, providing access to a digital watermark, providing access to said article, providing access to information contained within said article, and providing a key for decrypting encrypted information. 
   
   
     24. An article as in  claim 18 , wherein said first predetermined excitation source and said second predetermined excitation source comprise one of a same excitation source or two excitation sources.